Git instance preference improvements

[rhys-vdw]

I have two git instances that I change between, because one works with WSL and the other works with regular git.

This flow could be greatly improved by these options (from least to most useful):

Remember the custom instances I specify in the preferences dropdown:

Currently I need to navigate to the folder every time.

Specify a git instance per repository.

Changing a global instance is not particularly helpful for me. The repo is either in WSL filesystem or in Windows filesystem. So I need to change git instance every time I change tab.

Insofar as there is value in changing git instance, I feel like a per-repo binding would be most useful.

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Honestly, even if you could just open the "Custom git instance..." file picker to the same folder as last time that would be an enormous help to me. It opens at my home folder every time.